Apparatus for making sound records



Dec. 20, 1932. 1 KAHN 1,891,822

APPARATUS FDR MAKING SOUND RECORDS Filed Nov. 30, 1929 a 2 fiL'Q-MM K4/3 V? an? 1 Patented Dec. 20, 1932 UNITED STA 'rnnonon man, or nmmemu!urmrus son name som nouns Application filed November so, 1929; Serialso.

My invention relates to a machine for making sound records onnon-metallic filmsf More particularly, my invention relates to machinesin which the record is obtained by machining the edge of the film. I

It is an object of my invention to provide means for machining an exactrecord. To this end I equip my machine with a singlepointed cutter,

It has already been proposed to cut grooves in phonograph records wlth asin le-pointed tool but the point of this tool is b unted. It has alsobeen proposed to machine metal or other bands with a milling cutter forobtaining the?! eon a sound record at the edge or edges. Obviously, witha blunted tool or a milling cutter it is impracticable to obtain aperfect record as many details are lost. I have found that it ispossible to obtain a really good record only with a single-pointedcutter.

The cost of the records is much reduced .by using scrapped picture filmswhich are very cheap, or films without the sensitive layer. The cost maybe further reduced by subdividing films of normal width intoseveralnarrow strips which are more handy than normal Obviously, I mayuse as sound records picture films which are still in good condition andthus obtain combined sound and picture films As a burr may form whenmachining the edge which when it gets into contact with the st) lus ofthe receiving instrument, may cause undesirable noise and indistinctrendering, the cutting edge is preferably made concave that the stylusis not interfered with by the burr.

'I he cutter is preferably made of very hard material, such as preciousstone or special steel so that it will not get blunt and requireexchanging.

In the accompanying drawing a machine embodying my invention isillustrated by way of exampie.

In the drawing Fig. 1 is an eievation, Fig. 2 is a plan view of themachine,

410,8, all in mylmtir' 81, ms.

Fig. 3 is an perspective illustration of the cutter,

Fi 4 is a perspective illustration, drawn to a arger scale and showingthe record on the edge of a single film, and Fig. 5 is a similarillustration showing three films machined together.

Refe nowtothedra ,Iisafilm band, 2 an 3 are feed rollers y which theband is moved in the direction ofthe arrow, Figs. 1, 4 and 5 arefiriglllel guides between which the moving is held to prevent bucklingunder the pressure of the cutter, 6is asoundbox, and'listhe cutter,withits concave cutting edge 8. The concave cuttin edge of the cutter makesa convex o the film band and kee the stylus away rom anfi burr which mayorm.

eferring now to Fig. 4

10isarecordonitsedge.

Referring to Fig. 5; 11,12, and 13 are'three films which are placed sideby side and machined together.

A machine for sound records comprising a sound box, a cutter adapted tobe operated by said sound box, means for feedmg a film said cutter ina'straight' line, with its presented to said cutter, and .a curvedcutting edge on said cutter with its gigpave side turned toward the edgeof said 11; testimony whereof I aflix my signature.

TIEODOB KAHN. 85

